T-Mobile could face a class action lawsuit over claims that it made employees work without pay using mobile phones and email devices. The US suit highlights concerns about employee rights at a time of always-on communications.

Law firm Pelton and Associates in New York has put out a call for people to join a class action over the issue. Class action suits are a way for a single hearing to judge the cases of many people in very similar situations. They can result in payouts of billions of dollars in damages because of the potentially large number of litigants. There is no equivalent form of action in the UK.

According to its court filing, the case is currently being taken on behalf of three former employees of T-Mobile.

It says that the three men were asked to work unpaid by opening and closing T-Mobile shops, arranging rotas and participating in calls while not logged into the company's time-recording system.

"The Complaint alleges that T-Mobile hired retail sales associates and supervisors who were required to work well over forty hours per week yet were not paid wages or overtime compensation for all of the hours that they were required to work," said a statement from Pelton and Associates.

"The Complaint alleges that these employees were issued T-Mobile smart devices and were required to review and respond to numerous T-Mobile-related emails and text messages at all hours of the day and night, whether or not they were logged into T-Mobile's computer-based timekeeping system," it said.

The suit claims that T-Mobile broke US employment law as well as state laws in New York and California.

"The Complaint also alleges that the employees were required to take and place T-Mobile-related telephone calls, participate on T-Mobile conference calls and to work 'off the clock' during scheduled lunch breaks," said the law firm's statement.

"While plaintiffs were classified as non-exempt hourly employees they were typically required to spend 10-15 hours per week reviewing and responding to email, texts, phone calls, participating on conference calls and studying/reviewing corporate documents for which they were not paid any compensation," said the court filing.

T-Mobile told the Wall Street Journal that it was in compliance with the law.

The case highlights growing concern over employee welfare when email devices such as the Blackberry – long nicknamed the Crackberry for its supposedly addictive hold over executives – are becoming increasingly commonplace.

Rutgers University management professor Gayle Porter told podcast OUT-LAW Radio earlier this year that though it seems unlikely now, companies could in the future face successful class action lawsuits over technology use and even addiction.

She said that arguing that people choose to look at devices outside of work hours may not be enough of a defence in court.

"You think, oh it's a personal choice, how could you hold someone else liable for that? [But] we have done it – over and over again. When you look at the history of court actions on things that we might say really are personal responsibility, we have got that piece," she said. "When we look at how litigious as this society is everybody wants to sue for everything."